Pneumatic-hammer safety device.



Jaw/afar. W fimmrw M. E. ARKILLS. PM U TIC HAMMER SAFETY DEVICE.

PLICAIIOII man use, 2:. ms.

1,267, 163. Patented 2| 8.

2 SHE NEE M. E. ARKILLS. PNEUMATIC HAMMER SAFETY DEVICE. APPLICATION men 056,1". 19ml ll 34 5' w .25 a5 32 .51

. M I ,440., 221 i? Patented May 2], 8.

2 SHEETS-SHEE q Chicago, in the county of mmvnr E. KILLS, OI CHICAGO, ILLINOIS.

mmTIG-HAHHEB SAFETY DEVICE.

Specification 01' Letters latent.

Patented May 21, 1918.

Application filed December 21, 1916. Serial No. 188,161.

To all whom it may concern:

Be it known that I, Munvnv E. AnKILLs, a citizen of the United States, residing at Cook and State of Illinois, have invented certain new and useful Improvements in Pneumatic-Hammer Safety Devices, of which the following is a specification.

The invention has for its primary object provision of efiicient mechanism for holding the tool to its seat, said mechanism capable of being quickly released and enga ed relative to the tool without the possi ility of loss of parts or of personal injury, and being automatic in its releasing and clamping action when actuated by the operator and proof against accidental operation.

In order that the invention may be readily understood by those skilled in the art preferred and modified embodiments of the same are set forth in the accompanying. drawings and in the followin detailed description based thereon. Obviously the invention is susceptible of embodiment in other and varied constructional forms, wherefore it will be understood that the drawing and description are to be taken in an illustrative and not in an unnecessarily limiting sense.

In the drawingsq t Figure 1 is a composite view showing a pneumatic hammer embodying the invention, partly in side elevation and partly in ion 'tudinal section;

. ig. 2 is a transverse section on the line 2-2 of Fig. 1;

flgig. 81is a similar section on the line. 3-3 0 1g.

Fig. 4 is a detail view of one of the clamping aws; j lgs. 5, 6, 8 and 9 are fragmentary longitudinal sectional views of modifications;

Fig. 5 is a detail view of one of the clampin jaws shown in Fig. 5; and

Fig. is a transverse section on the line 77 of Fig. 6.

The invention is herein shown and described in connection with a pneumatic hammer of the eneral type of that shown in the patent to lois 1,138,877, but constitutes an improvement thereover in the manner of mounting and operation of the tool holding jaws, whereby the releasing and clam ing action of the jaws is rendered automatlc and disassociation of the parts is efl'cotually precluded.

Having particular reference to Figs. 1 to 4 of the drawin reference numeral 11 designates the cy mdrical shell or barrel of a pneumatic hammer of ordinary construction within which is adapted to operate the piston-hammer, not shown. Inserted in the forward end of the barrel is a die or tool 12 by means of its shank 13. Immediately to the rear of the tool head 12 is a portion of reduced diameter 14 and immediately to the rear thereof is a shoulder 15, the forward and rear faces of the shoulder 15 forming abutments to limit the reciprocation 0 the tool under the impact of the hammer.

A short distance to the rear of the forward end of the barrel 11 is formed an annular groove 16 and forwardly of said groove the diameter of the barrel is slightly reduced. A series of se ental lever jaws 17 are arranged about t e reduced end 11 the groove 16. Each of these jaws has an outwardly extending heel flange 19 and an inwardly extending lip flange 20 at its forward end. Taken together, the lurality of jaws 17 individually segmental in shape, constitute a' com lete circle enveloping the tool in its reduce 20 extending closely adjacent the reduced portion 14 of the tool and within the space included between the head 12 and the shoulder 15 of said tool. It will be readily understood that when held together to form a complete circle the lip flanges 20 will serve as a forward abutment for the shoulder 15 to limit the forward movement of the tool 12. In Fig. 1 the jaws are shown in clampinglrelation to the tool.

ncircling the forward portion on the barrel of the hammer is a sleeve 21 having a knurled actuating portion 22 and a removable forward extension 23 detachably connected to the sleeve 21 by means of the threads 24. The sleeve 21 is undercut at 25 as is also the barrel at 26 provided with an exterior oove to accommodate the leaf spring 27 w on the latter is depressed. 0n the forward end of the sleeve 21 is rovided a shoulder 28 and the forward on of the extension 23.. is inwardly flanged to rovide a shoulder 29, which closely enve ops the forward ends of the jaws 17.

Assuming the several parts of the device to be in the position shown in Fi 1, if it be desired to release and remove t e tool 12 from the device the leaf spring 27 is de- .of the barrel with toe flanges 18 resting in portion 14, the lip flanges I therein by stamping. an

' 29 to move several jaws being separa vs 26 and by means of he knurled ortion 22 of the sleeve 21 the with it eflange back out of enveloping relation to the forward ends of the jaws and to enage the heel flange 19 of the aws It Will be seen from Fig. 1 that that portion of the barrel immediately to the rear of the r ear end of the jaw is beveled, and the striking of the flange 29 against the heel flange 19 will cause the jaw to ,rock flange 18', the

pressed into the groo latter is moved to the rear carry the sleeve extension 28 and causing t forward ends of each of the jaws moving outwardly radiall so that the several aw segments instead 0 constituting a closed cylinder will form a flaring or trumpethaped mouth to the hammer, the ted. The tool 12 may now be readily removed from within the jaws and the forward end of the barrel. The same tool having been replaced or another substituted, the sleeve 21 and its extension 23 is moved forward, the flanges 29 of the sleeve extension riding upon the several segmental jaws and causing t e same to rock inwardly to a clamping posi ion about the tool as before, the flan 29 and the shoulder 28 eoiiperating to hol the jaws in the position indicated in Fig. 1, while the spring 27 will snap to the position shown against the knurled ortion of the sleeve 21 and thus prevent its accidental retraction to release the jaws.

In this embodiment of the invention I have shown the jaws as seven in number. Obviously there may be more or less. There should be three or more in order to facilitate the rocking of the same upon their fulcra in the groove 16.

In Fig. 5 is shown a form of construction in which a one piece sleeve 80 is used the forward movement of which is limited b impingement against a flange 31 forme upon each jaw 32 while its movement to the rear in the locked position is restricted as before by the spring 83 and its rearward movement in the unlocked (position is limited by means of the screw hea 34. In this form of the invention the segmental jaws 32 are provided with toe flanges 35 fulcrumed within the annular groove 36. Instead of roviding positive means such as the eel flanges 19 for rocking the jaws to release the tool as in the construction formerly described, each of the jaws 82 has formed integral spring tongue 87 which bears downwardly upon the forward end of the barrel and tends to force the jaws upwardly causing the several jaws to separate radially as before to permit the withdrawal of the tool 12. The range of movement of the sleeve to the rear is such as not to entirely clear the jaw and conseuently the several jaws are prevented from ssociation.

Q42 and the heel flange 48,

names In Fig. 6 is shown another form of construction, the segmental jaws havmflg the forward mturne lip flange 41, the toe ange the jaws adapted to rock within the groove 44. A sleeve 45 is provided having a helical which filays a pin 47 seated in the barrel of the ammer. In this case a sleeve extens1on 48 is screw threaded upon the forward gortlon of the sleeve 45 and has an inturned ange 49 between which and the forward end of the sleeve pro er 45 the heel flanges 43 of the jaws are con% the rear of the sleeve 45 is secured by means of a screw 50 a spring 51 which extends into an undercut face 52 in the rear of the sleeve. v

Ifhe upper wall or roof of the undercut portion 52 is oorru ated or roughened as indicated at 53 to rictionally engage with the forward end of the sprin 51. It will be readily underst od that w en the sleeve 45 is rotated, the engagement of the pin 47 in the slot 46 will cause the sleeve 45 to move to the rear thus rocking the jaws 40 upon the toe flange 42. The frictional engagement between the forward end of the sprmg 51 and the roughened surface 53 will cause the angular adjustment of the sleeve 45 to be maintained either in the locked or unlocked position of the 'aws 40.

In Fig. 8 iss own a form of construction in which the jaws are themselves of spring metal having the forward lip flange 61, the toe flange 62 seated in an annular groove and with an extension 63 hearing u on the beveled forward end of the barre. The one piece sleeve 64 is arranged to reciprocate so as to close the spring jaws 60 or to permit them to open under the influence of the spring extension 63 bearing upon the hammer. The movement of the sleeve 64 to the rear is limited in the clamped position of the tool by the spring 65 and in its rearmost osition with the clamping jaws expanded y im inging against the head of the screw 66, w ile its forward movement is limited by its shoulder 67.

In Fig. 9 is shown yet another form of construction wherein the spring jaws having the forward lip flange 71 are at the rear bent upon themselves to form the toe. flange 72 and the spring extension 73. The jaw segments are confined or permitted to expand by the one piece sleeve 74 arranged to reciprocate u on the barrel of the hammer and provid with a longitudinal slot 75 within which plays a pin 76 mounted in the barrel. The rearward movement of the sleeve 74 is limited in the closed position of the jaws by the spring 77. a

It will be observed that in all of the emy as the sleeve is actuated, either by the rocking of slot 46 within ned. To the barrel at the jaw segments as an entirety, the being rigid as in Fig. 1, or by reason of t eir inherent elasticity when the confining action of the sleeve is removed. In their expanded position, they are yet confined by the sleeve within the groove of the barrel in such manner that they cannot become loose and disassociated from the other parts of the device except by aflirmative action of the operator where it is desired to replace or to obtain access thereto for some other reason. In the latter event, the sleeve extension 23 or 48 would be unscrewed in that form of the device shown in Figs. 1 and 6, or the screw 34 or 66 or 7 6 would be removed in the device shown in F 5, 8 and 9 so as to ermit the sleeve to move to the rear a su cient distance to clear the jaws.

I claim:

1. Tool holding mechanism for neumatic hammers comprising a pluralit o jaws carried by the hammer barrel and embracing a tool, means to tilt the jaws to ex and their forward ends whereby to release tli e tool and to izontract the jaws whereby to clamp the too 2. Tool holding mechanism for pneumatic hammers comprising three or more segmental jaws carried by the hammer barre and embracin a tool, and means to tilt the jaws to expan their forward ends whereby to release the tool and to contract the jaws whereby to clamp the tool.

3. Tool holding mechanism for pneumatic ammers comprising a plurality of segmentaljaws fulcrumed at their rear ends on the hammer barrel and havin tool engaging flanges at their forward on s, and a sleeve movable on the barrel and acting on the jaws to rock the same into and out of clamping relation to the tool.

4. Tool holding hammers comprlsing a plurali of mental jaws, the jaws fulcrum at their rear ends to tilt from a general parallel osition clampin a tool to an expanded aring position re easing the tool, and a sleeve embracin the j awe and movable on the hammer arrel. v

5. Tool holding mechanism for pneumatic hammers comprising a plurality of segmental jaws having rear an forward flanges engagin the hammer, barrel and tool, the 'aws fu crumed on their rearflan to tilt rom a general parallel position clamping the too to an expanded flaring position releasing the tool, and a sleeve embracing the jaws and movable on the hammer barrel.

6. Tool holding mechanism for pneumatic hammers comprlsing a plurality of segmental jaws having inwardly extending forward tool engaging flanges and inwardly and outwardly extending rear flanges, the barrel grooved to receive the inwardly extending rear flanges, a sleeve movable Iongitudinally of the barrel and embracing the aws, and means carried by the sleeve to engage the outwardly extending rear flange of the jaws upon the movement of thesleeve to the rear to tilt the jaws on their inwardly extending rear flanges-to an expanded flaring position whereby to release the tool.

mechanism for pneumatic 

